IPC-TM-650 EN 2022 试验方法.pdf - 第727页

held for 30 minutes. The humidity should then be increased to 93%RH. 5.6.3.3 Expose specimen to the above environment for 240 hours (10 days). M and H fluxes may be tested in the cleaned, as well as uncleaned, condition.…

5.3.3

Immerse

in 5% sulfuric acid (by volume) at 65 ± 5 °C

[149 ± 9 °F] for one minute to remove the tarnish film.

5.3.4

Immerse

in a solution of 25% m/v ammonium persul-

phate (in 0.5% v/v sulfuric acid) at 23 ± 2 °C [73.4 ± 3.6 °F]

for one minute to etch the surface uniformly.

5.3.5

Wash

in running tap water for five seconds. Immerse

in 5% sulfuric acid (by volume) at 23 ± 2°C [73.4 ± 3.6 °F] for

one minute.

5.3.6 Wash

for five seconds in running tap water, then rinse

thoroughly in deionized water.

5.3.7

Rinse

with acetone.

5.3.8

Allow

to dry in clean air.

Note: Use the test piece as soon as possible or store up to

one hour in a closed container.

5.4

Solder for Liquid or Paste Flux Test

5.4.1

Weigh

a 1.00 ± 0.05 gram specimen of solid solder.

5.4.2

Degrease

the solder specimen with a suitable neutral

organic solvent such as acetone, or petroleum ether.

5.4.3

Solder

may be in the form of pellets or tight spirals of

solid solder wire.

5.5

Test

5.5.1

Heat

solder pot so that solder bath stabilizes at 235 ±

5 °C [455 ± 9 °F].

5.5.2

Liquid or Paste Flux

5.5.2.1

Place

0.035 g of flux solids into the depression in

the test panel. Add the solid solder pellets or spirals.

5.5.2.2

Using

tongs, lower the test panel onto the surface of

the molten solder.

5.5.2.3

Allow

the test panel to remain in contact with the

bath until the solder specimen in the depression of the test

panel melts. Maintain this position for5±1seconds before

removing the test panel from the bath. Cool the test panel to

room temperature.

5.5.3

Cored Wire or Cored Preform

5.5.3.1

Place

1 gram of flux cored wire or perform into the

depression in the test panel.

5.5.3.2

Using

tongs, lower the test panel onto the surface of

the molten solder.

5.5.3.3

Allow

the test panel to remain in contact with the

bath until the solder specimen in the depression of the test

panel melts. Maintain this position for5±1seconds before

removing the test panel from the bath. Cool the test panel to

room temperature.

5.5.4

Solder Paste

5.5.4.1

Place

0.3 g of solder paste into the depression in

the test panel.

5.5.4.2

Allow

the test panels to remain in contact with the

bath until the solder specimen in the depression of the test

panel melts. Maintain this position for 60 ± 5 seconds before

removing the test panel from the bath. Cool the test panel to

room temperature.

5.5.4.3

Alternately,

process the panels through a reflow sol-

dering process using the temperature profile recommended

by the vendor.

5.6

Humidity Exposure

5.6.1

Carefully

examine the test specimen at 20X magnifica-

tion for subsequent comparison after humidity exposure.

Record observations, especially any discoloration (see 8.2).

5.6.2

Preheat

test panel to 40 ± 1 °C [104 ± 1.8 °F] for 30

± 2 minutes.

5.6.3

Humidity Soak

5.6.3.1

Place

the test specimen vertically in a preset humid-

ity chamber at 40 ± 1 °C [104 ± 1.8 °F] and 93 ± 2% relative

humidity.

5.6.3.2

Alternately,

the specimen may be placed in a tem-

perature humidity chamber and heated to 40 °C [1.8 °F] and

IPC-TM-650

Number

2.6.15

Subject

Corrosion,

Flux

Date

06/04

Revision

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held

for 30 minutes. The humidity should then be increased to

93%RH.

5.6.3.3

Expose specimen to the above environment for 240

hours (10 days). M and H fluxes may be tested in the cleaned,

as well as uncleaned, condition. Specimens shall be cleaned

per the manufacturers instructions.

5.7

Evaluation

5.7.1

After

the exposure period, remove test specimens

from humidity chamber, examine at 20X magnification and

compare with observations noted in 6.5 (see 8.2).

5.7.2

For

purposes of this test method, the following defini-

tion of corrosion shall prevail: ‘‘A chemical reaction between

the copper, the solder, and the constituents of the flux resi-

dues, which occurs after soldering and during exposure to the

above environmental conditions.‘‘ Corrosion for this test is

classified as follows:

5.7.2.1

Minor Corrosion

Any

initial change of color, which

may develop when the test panel is heated during soldering,

is disregarded. Discrete white or colored spots in the flux resi-

dues or a color change to green-blue without pitting of the

copper or formation of excrescences is regarded as

minor

corrosion.

5.7.2.2

Major Corrosion

Any

initial change of color which

may develop when the test panel is heated during soldering is

disregarded. Subsequent development of green-blue discol-

oration with observation of pitting of the copper panel or

excrescences at the interfaces of the flux residue and copper

boundary, is regarded as

major

corrosion.

Notes

6.1

Questionable

results may be confirmed by analyzing the

suspected corrosion via Energy Dispersive X-ray Spectros-

copy (EDS) for the presence of copper.

6.2

Color

photos before and after the test are valuable tools

in identifying and documenting corrosion.

6.3

Safety

Observe

all appropriate precautions on MSDS

for chemicals involved in this test method.

IPC-TM-650

Number

2.6.15

Subject

Corrosion,

Flux

Date

06/04

Revision

age3of3

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1.0

Scope

This

procedure is a rapid means for evaluating

glass epoxy laminate integrity on different lots of base lami-

nate materials before placing materials on the production

floor, and thereby reducing the cost of processing material

which may later prove to be defective.

2.0

Applicable Documents

IPC-A-600

Acceptability

of Printed Boards

IPC-MI-660

Guidelines

for Incoming Inspection of Raw Mate-

rials

3.0

Specimens

The

samples of qualification or incoming

production test coupons shall be 4.0 inch x 4.0 inch x 1/16

inch thick (see 7.1) and etched using the standard commer-

cial practices procedure of the individual test facility. The test

coupons can be taken from any part of the laminate. The test

strip may be sheared, but the individual test coupons shall be

sawed and their edges sanded.

4.0

Number of Test Coupons to be Tested

Five

coupons

shall be tested and may arbitrarily contain a known ‘‘pass’’

and ‘‘fail’’ control coupon. However, if a failure mode is estab-

lished, a second set of 5 samples shall be tested from another

laminate and this set must contain a pass and fail control. The

number of test coupons tested at any one time should be lim-

ited to the capacity of the pressure vessel being used.

5.0

Apparatus

5.1

Any

standard laboratory autoclave pressure vessel hav-

ing a 6-quart capacity. A commercial household 6-quart stain-

less steel pressure cooker capable of developing 15 psi pres-

sure (the 15 psi pressure set at the location of the test) may

be used if equipped with a properly calibrated pressure gauge

to maintain 15 psi ± 0.5 psi pressure.

5.2

laboratory solder pot capable of maintaining a solder

bath (SN 60) at 500°F–0°+10°F.

5.3

Stop

watch.

5.4 Solder

pot containing SN 60/40 solder.

6.0

Test

6.1 Preparation

6.1.1

Cut test coupons only by sawing, and sand the edges

of the specimens so they are smooth.

6.1.2

Etch

specimens to remove metal foil except in any

areas which may have identification codes.

6.1.3 Apply

permanent identification markings on speci-

mens on the end that will not be immersed in the solder pot.

6.1.4

The

specimens will be placed in a suitable rack for

suspending in the pressure vessel. The specimens should not

be drilled for suspension as this creates a path for moisture

incursion, giving false results.

6.1.5

Pour

water into pressure vessel to approximately 1.0

inch depth. Cover and bring to a boil without pressurizing.

6.2

Test

6.2.1

When

steam is observed at the vent, uncover and

suspend specimens vertically over boiling water, being careful

not to allow specimens to touch each other or the walls of the

pressure vessel. This step must be done rapidly to avoid

undue cooling of the water and pressure vessel.

6.2.2

The

heat-up time should be controlled at 7 minutes ±

1 minute.

6.2.3

After

reaching 15 psi. maintain this condition for 30

minutes+2–0minutes.

Note:

Other

pressure vessel dwell times may be agreed upon

between user and vendor.

6.2.4

the end of the exposure time, cool and vent the

pressure vessel as recommended by the manufacturer.

6.2.5

Carefully

remove the hot specimens from the pressure

vessel and blot dry with paper towel (see caution notes).

6.2.6

The

specimens shall be maintained at ambient tem-

perature, and within 10 minutes it shall be immersed vertically

(with the edge parallel to the solder surface) into the solder

bath which is maintained at either 500°F–0+10°F for 20

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.6.16

Subject

Pressure

Vessel Method for Glass Epoxy Laminate

Integrity

Date

7/85

Revision

Originating Task Group

N/A

Material

in this Test Methods Manual was voluntarily established by Technical Committees of the IPC. This material is advisory only

and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this

material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.

Equipment referenced is for the convenience of the user and does not imply endorsement by the IPC.

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